來自動物研究所科技信息中心的消息，中國科學院動物研究所分子生態學和進化研究組的研究人員運用分子生態學的研究手段，從多個獨立微衛星DNA位點對覆蓋飛蝗中國分布區的25個樣點的1300多個標本進行了綜合分析。這項研究成果一方面驗證了飛蝗經典分類的一些結論，另一方面則指出了對由Boris Petrovitch Uvarov (1889-1970)（被學界譽為「蝗蟲之父」）在上世紀三十年代建立的關於東亞飛蝗的有關權威觀點進行修正的必要性。
飛蝗是一種重要農業害蟲，具有很強的遷飛能力，其分布區比任何其他蝗蟲都更廣闊，幾乎覆蓋了東半球的整個溫、熱帶地區。然而，基於生物學或形態學差異，飛蝗僅在中國就鑑定出了三個亞種，而在世界範圍內則存在至少九個亞種——這跟其遷飛能力是相矛盾的，學術界對此也一直存留爭議。
張德興教授的研究團隊運用分子生態學的研究手段，從多個獨立微衛星DNA位點對覆蓋飛蝗中國分布區的25個樣點的1300多個標本進行了綜合分析。他們發現，儘管飛蝗具有很強的遷飛擴散能力，中國的飛蝗確實分為北方種群、南方種群和西藏種群三個具有顯著遺傳差別的種群，但是與傳統認識不同的是，廣布於中國中、東部的飛蝗並非東亞飛蝗，而是應隸屬於亞洲飛蝗亞種。他們的研究成果一方面驗證了飛蝗經典分類的一些結論，另一方面則指出了對由Boris Petrovitch Uvarov (1889-1970)（被學界譽為「蝗蟲之父」）在上世紀三十年代建立的關於東亞飛蝗的有關權威觀點進行修正的必要性。
該研究團隊還進一步分析了飛蝗在中國形成和維持三個具有顯著遺傳差別的種群的原因，指出：歷史生物地理學因素可能是導致形成這三個地理種群的關鍵原因，特別是更新世冰期-間冰期旋迴事件，使得飛蝗種群退縮到不同的避難地並發生適應性分化，現今的種群是氣候和生態條件恢復後重新建群的結果；而飛蝗中國北方種群很可能是在末次冰期後由中亞的避難地擴散而來。他們還指出，儘管飛蝗的遷飛擴散能力非常強，但適應性差異使得三個飛蝗種群能夠維持它們目前的分布格局。這些關於中國飛蝗的研究結果無論對於飛蝗研究還是對中國的動植物群體的譜系生物地理演化研究都具有重要意義，例如，它揭示出生物的演化歷史對於塑造具有很強擴散能力的物種的種群分化和分布模式的重要性；又如，鑑於我國東部地區的飛蝗和蒙新高原及東北的飛蝗共同組成北方種群，因而共同構成了一個地區間可進行廣泛基因交流的遺傳群，在全球變化氣候逐漸變暖的趨勢下，飛蝗有逐漸向北擴散的可能，東北地區將會逐步具有飛蝗大發生的所需要的必要氣候條件；而相比之下，南方種群（如海南的飛蝗）對於華北地區的影響則可能較小。（生物谷Bioon.com）
生物谷推薦原始出處：
BMC Evolutionary Biology 2009, 9:144doi:10.1186/1471-2148-9-144
Unexpected relationships of substructured populations in Chinese Locusta migratoria
De-Xing Zhang1,2 , Lu-Na Yan1,4 , Ya-Jie Ji1 , Godfrey M Hewitt3 and Zu-Shi Huang1
1 State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, PR China
2 Center for Computational and Evolutionary Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, PR China
3 School of Biological Sciences, University of East Anglia, Norwich NR4 7TJ, UK
4 Current address: College of Biological Science and Engineering, Hebei University of Science and Technology, Shijiazhuang, Hebei 050018, PR China
Background
Highly migratory species are usually expected to have minimal population substructure because strong gene flow has the effect of homogenizing genetic variation over geographical populations, counteracting random drift, selection and mutation. The migratory locust Locusta migratoria belongs to a monotypic genus, and is an infamous pest insect with exceptional migratory ability – with dispersal documented over a thousand kilometers. Its distributional area is greater than that of any other locust or grasshopper, occurring in practically all the temperate and tropical regions of the eastern hemisphere. Consequently, minimal population substructuring is expected. However, in marked contrast to its high dispersal ability, three geographical subspecies have been distinguished in China, with more than nine being biologically and morphologically identified in the world. Such subspecies status has been under considerable debate.
Results
By multilocus microsatellite genotyping analysis, we provide ample genetic evidence for strong population substructure in this highly migratory insect that conforms to geography. More importantly, our genetic data identified an unexpected cryptic subdivision and demonstrated a strong affiliation of the East China locusts to those in Northwest/Northern China. The migratory locusts in China formed three distinct groups, viz. (1) the Tibetan group, comprising locusts from Tibet and nearby West China high mountain regions; this is congruent with the previously recognized Tibetan subspecies, L. m. tibetensis; (2) the South China group, containing locusts from the Hainan islands; this corresponds to the Southeast Asia oriental tropical subspecies L. m. manilensis; (3) the North China group, including locusts from the Northwest and Northern China (the Asiatic subspecies L. m. migratoria), Central China and Eastern China regions. Therefore, the traditional concept on Locusta subspecies status established from Uvarov in 1930s needs to be revised. The three groups of locusts probably have separate evolutionary histories that were most likely linked to Quaternary glaciations events, and derived from different ancestral refugial populations following postglacial expansions.
Conclusion
The migratory locust populations in China have differentiated into three genetically distinct groups despite high dispersal capability. While this clarified long-standing suspicions on the subspecific diversification of this species in China, it also revealed that the locusts in the vast area of East China are not the oriental subspecies but the Asiatic subspecies, an unexpected substructuring pattern. The distribution pattern of the three locust groups in China may be primarily defined by adaptive differentiation coupled to Quaternary glaciations events. Our results are of general significance both for locust research and for phylogeographical study of flora and fauna in China, illustrating the potential importance of phylogeographical history in shaping the divergence and distribution patterns of widespread species with strong dispersal ability.